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Bitumen-Derived Onion-Like Soft Carbon as High-Performance Potassium-Ion Battery Anode
Small ( IF 13.0 ) Pub Date : 2022-08-27 , DOI: 10.1002/smll.202203494
Wen Tan 1, 2 , Lina Wang 1, 3 , Kun Liu 1, 2 , Zhouguang Lu 1, 2 , Fan Yang 4 , Guangfu Luo 1, 3 , Zhenghe Xu 1, 2, 5
Affiliation  

Potassium-ion batteries (PIBs) have been regarded as a competitive alternative for lithium-ion batteries, owing to the natural abundance, low cost, and similar rocking-chair working mechanism of potassium element. However, it is challenging to simultaneously prepare suitable potassium ion anode materials of low voltage plateau, high capacity, and long cycle life. In this work, onion-like soft carbon (OLSC) of high heteroatom content is prepared by using solvent-sensitive self-assembly properties of asphaltene molecules. The OLSC electrode exhibits a low voltage plateau because of a high degree of graphitization. Meanwhile, it possesses excellent cycling stability and rate capability due to the high stability of the onion-like structure and fast transport of potassium ions, the latter of which is caused by heteroatom-induced expanded interlayers as found by first-principle calculations. Compared with existing carbon materials, the OLSC synthesized in this study exhibits a high reversible capacity of 466 mAh g–1 at 20 mA g–1, a reversible capacity of 222 mAh g–1 and capacity retention of 95% after 1600 cycles at 1 A g–1. This work connects the nanostructure of carbon materials and electrochemical performance and provides new insights in improving carbon-based anodes for PIBs.

中文翻译:

沥青衍生洋葱状软碳作为高性能钾离子电池负极

钾离子电池(PIBs)由于钾元素的天然丰富、低成本和类似的摇椅工作机制,被认为是锂离子电池的竞争替代品。然而,同时制备合适的低电压平台、高容量和长循环寿命的钾离子负极材料具有挑战性。在这项工作中,利用沥青质分子的溶剂敏感自组装特性,制备了高杂原子含量的洋葱状软碳(OLSC)。由于高度石墨化,OLSC 电极表现出低电压平台。同时,由于洋葱状结构的高稳定性和钾离子的快速传输,它具有优异的循环稳定性和倍率性能,后者是由第一性原理计算发现的杂原子引起的膨胀夹层引起的。与现有的碳材料相比,本研究合成的 OLSC 具有 466 mAh g 的高可逆容量–1在 20 mA g –1下,可逆容量为 222 mAh g –1 ,在 1 A g –1下 1600 次循环后容量保持率为 95% 。这项工作将碳材料的纳米结构和电化学性能联系起来,并为改进 PIB 的碳基阳极提供了新的见解。
更新日期:2022-08-27
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